Strand covering apparatus



M r h 21, 1 4 w. T BARRANS 2,344,586

STRAND COVERING I APPARATUS Filed March 31, 1942 m l/E/V TOR W. T. BARRA NS Patented Mar. 21, 1944 STRAND COVERING APPARATUS William T. Barrans, Towson, Md., assignor to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York Application March 31, 1942, Serial No. 436,985

13 Claims.

This invention relates to strand covering apparatus and more particularly to apparatus for producing textile covered, extensible and retractile cords.

In Patent 2,200,323, granted May 14, 1940, on an application filed jointly by W. T. Barrans and P. M. Cole, there is described a strand covering machine designed to produce textile covered, extensible and retractile cords. In the machine shown in that patent, means are provided for applying a textile covering to a plurality of strands to form a cord and the thus-formed cord is Withdrawn from the covering mechanism by means of an elongated axial capstan provided with a knurled portion which was intended to engage the textile covering and exert a pulling force thereon.

The problem of providing an eflicient capstan for advancing retractile cords is complicated by the fact that the usual types of retractile cords, such as those used in connection with telephone apparatus, are relatively small in diameter and the helices into which they are formed are also of small size. Consequently, in the operation of thetype of capstan shown in said Patent 2,200,323 some difficulty was encountered because the indentations in the knurled surface thereof were too shallow and too close together to take a sufficient grip upon the textile covering. As a result, a varying amount of slippage sometimes occurred and helical cords of uneven length and diameter occasionally were produced.

An object of the invention is to provide apparatus for making helical extensible and retractile cords in which the helices have uniform convolutions.

In accordance with one embodiment of the invention, an apparatus for continuously forming a textile-covered, extensible and retractile cord is provided with an axial delivery capstan having rectangular, longitudinal grooves formed therein for gripping the textile covering on the cord so as to advance the cord into a uniform helix.

Other objects and features of the invention will be apparent from the following detailed description of a specific embodiment thereof, taken in conjunction with the accompanying drawing, in which Fig. 1 is side elevation of a portion of strand covering apparatus illustrating a delivery capstan and associated apparatus embodying the in vention, and

Fig. 2 is an enlarged sectional view of the delivery capstan taken on line 2-2 of Fig. 1.

The apparatus embodying this invention may be employed in connection with a braiding machine, knitting machine, serving machine or any other suitable device for applying a textile covering upon a plurality of strands to produce a composite cord which is intended to be formed into an extensible and retractile helix. For example, it may be employed with extremely satisfactory results in conjunction with a braiding machine of the type discolsed in the aforementioned Patent 2,200,323. Since the type of braiding, knitting or serving machine with which the apparatus is to be used may be of conventional design and the strand-covering apparatus does not form a part of the invention, no specific type of textile applying mechanism is shown in the accompanying drawing.

Referring now to the drawing, Fig. 1 illustrates an axial delivery take-up means which may be applied to a machine for applying textile coverings to strands such as has been referred to hereinabove. This take-up meanscomprises an arm [0 which accommodates a bearing II for a shaft l2. The bearing H is provided with an extended portion 14 of reduced diameter to which is secured, by means of a set screw IS, a forming cam 16 within which the shaft I2 is free to rotate.

The portion of the shaft l2 which extends to the left of the forming cam l6 as seen in Fig. 1 is made in the form of an elongated spindle having a relatively long cylindrical axial delivery portion [8 and a shorter cylindrical capstan portion 20 which is somewhat greater in diameter than the capstan portion It. The capstan portion 20 is provided with a plurality of rectangular grooves 22--22 formed therein to provide means for engaging the covering of textile covered cords to be acted upon thereby. Eachpf the rectangular grooves 22-22 extends longitudinally of the capstan portion 20 and has a straight side 23 which is parallel to but displaced from a diameter of the capstan. The side 23, together with the arcuate portion of the circumference of the capstan portion 20 which it intersects, forms a tooth 24 which will engage the irregularities in the surface of the textile covering in the cord.

While the number of the grooves may be varied to a considerable extent, four such grooves are provided in the embodiment of the invention disclosed in the drawing and the total length of the four grooves is approximately one-eighth of the circumference of the capstan portion 20. Thus for a capstan having a maximum diameter of one-half inch, the grooves would be approximately three-sixteenths inch wide. In a cap- 'tion 29 occurs.

stan of these dimensions, the sides 23 are offset from the respective diameters of the capstan portion which are parallel thereto, a distance of about three sixty-fourths of an inch and the sides 23 are approximately one-sixteenth inch deep. A groove of this dimension is approximately the same width as the diameter of the retractile cords customarily used in connection with telephone equipment.

In the operation of this axial delivery take-up means, a textile-covered cord 21, which is being continuously produced by means of any suitable apparatus such as a braiding machine, knitting machine or the like, is wrapped around the capstan portion 28 a number of times and the capstan is rotated in the direction indicated by the arrow from any source of power (not shown) which is connected to the shaft I2. The teeth 2424 formed by the grooves 22-22 engage the surface of the textile covering on the cord 21 and tend to advance the cord spirally around the capstan portion 20 and over the face 28 of the forming cam l6 which has a pitch approximately equal to the finished diameter of the helically formed cord. The combined pulling action of the capstan portion 26 and the forming action of the forming cam l6 cause the textile-covered cord 21 to be wound around the capstan portion 20 in the form of a helix having regular convolutions and will :at-the same time cause the thus-coiled cord to advance axially along the capstan portion 28 and onto the delivery portion It. The helically coiled cord may be withdrawn from the end of the delivery portion of the spindle 18 into any suitable collecting means or take-up mechanism.

The grooves 22-22, being relatively wide, permit the cord to partially enter the grooves and thereby present a portion of the body of the cord against which the teeth 2 -24 may act. This permits the delivery capstan to exert a substantially greater and more even pulling force upon the cord than is obtained when the capstan can engage only the covering ona cord,suc'h as is the case when a lmurled capstan is used. The coaction of the cord and the groovesis shown more clearly in Fig. 2 of the drawing wherein the extent to which the cord enters the grooves 22-22 is exaggerated somewhat for the purpose of illustration.

Since the grooves 22--22 exert a positive gripping action upon the textile covering of the cord 27, no slippage ofthe'corduponthe capstan por- As a result, textile-covered, extensible and retractile cords are producedin the form of helices having extremely unfiorm convolutions and having a uniformlinear length .of conductor per .unit length of the-coiledcord.

What is claimed is:

1. In an'apparatus for covering-strands, means .for applying a textile covering to strands:.to.form a cord, and an axial delivery capstan-for withdrawing from the strand-covering means the cord formed thereby, which capstan comprises a cylindrical member having a plurality of longitudinal,

rectangular grooves formed therein for engaging the cord and advancing the cord spirally around the capstan.

2. In an apparatus 'forcovering strahdameans for applying a textile covering to strands toform ya cord, and an axial delivery capstan for withdrawing from the strand-covering means the cord formed thereby, which capstan comprises an elongatedcylindrical member having formed therein a plurality of longitudinal, rectangular "grooves the width of which issubstantiallygreater than their depth for engaging the cord and advancing the cord spirally around the capstan.

3. In an apparatus for covering strands, means for applying a textile covering to strands to form a cord, and an axial delivery capstan for withdrawing from the strand-covering means the cord formed thereby, which capstan comprises a cylindrical member having formed therein a plurality of longitudinal, rectangular grooves having a width of approximately three times as great as their depth for engaging the cord and advancing the cord spirally around the capstan.

4. In an apparatus for covering strands, means for applying a textile covering to strands to form a cord, and an axial delivery capstan for withdrawing from the strand-covering means the cord formed thereby, which capstan comprises an elongated cylindrical member having formed therein a plurality of longitudinal, rectangular grooves the width of which is substantially equal to the diameter .of the cord for engaging the cord and advancing the cord spirally around the capstan.

5. In an apparatus for covering strands, means for applying a textile covering to strands to form a cord, and an axial delivery capstan for withdrawing from the strand-covering means the cord formed thereby, which capstan comprises a cylindrical member having four longitudinal, rectangular grooves Whose width is equal to about one-eight of the circumference of the capstan :for engaging the cord and advancing the cord spirally around thecapstan.

6. In an apparatusfor covering strands, means for applying a textile covering to strands to form a cord, and an axial delivery capstan for withdrawing from the strand-covering means the cord formed thereby, which capstan comprises a cylindrical member having a plurality of longitudinal, rectangular grooves ,formed therein for engaging the cord and advancing the cord spirally around the capstan, said grooves having amaximum depth of about one-eighth and a width of about .three-eighths of the diameter of ,the capstan.

7. Inan apparatus including meansflfor apply.- ing a textile covering tostrands to form a ;cord, an axial .delivery capstan for withdrawing from the strand-covering means the cord formed thereby which comprises a cylindrical member having a plurality of longitudinal, rectangular grooves formed thereinjfor engaging the cord'and advancing the cord spirally around the capstan, said grooves having a maximum depth of about one-eighth and a width of about 'three-eighths of the diameter of thecapstan and each groove having one side thereof parallel to but displaced from a diameter. ofgthe capstan.

8. In an apparatus including means for'applyinga textile covering tostrandstoform a cord, an axial deliverycapstan for withdrawing from the strand-covering means the cord formed thereby which comprises an elongatedcylindrical member having one portion-of greater diameter than another portion thereof, the portion of greater diameter being provided with a plurality of rectangular, longitudinal grooves ;for engaging the cord and advancing the cord arollnjd'the capstan and onto the portion of smaller diameter.

9. In an apparatus :includingrneans;v for applying .a textile covering to strands to ,form acord, an axial delivery take-up means ;comprising a rotatable spindle having a plurality ofgrectangular, longitudinal grooves .in one ,portionthereof forming a capstan foriengagingthe cord formed y h pp vinameans, and-.a, stationa y cam adjacent to said grooves for forming the cord into a helix around the capstan portion of the spindle and for urging the cord axially along the spindle.

10. In an apparatus including means for applying a textile covering upon strands to form a cord, an axial delivery capstan which comprises a rotatable cylindrical member having a plurality of longitudinal, rectangular grooves formed therein for engaging a cord formed by the strandcovering means, the grooves in said capstan being of sufficient width to permit substantial portions of the cord to enter the grooves and thereby present a mass of material against which the edges of the grooves may exert a pulling force to advance the cord spirally around the capstan.

11. In an apparatus for covering strands, means for applying a textile covering to strands to form a cord, and an axial delivery capstan constituting the sole means for withdrawing from the strand-covering means the cord formed thereby, which capstan comprises a cylindrical member having a plurality of longitudinal, rectangular grooves formed therein for engaging a plurality of convolutions of the cord and advancing the cord spirally around the capstan, the grooves being of suflicient width to permit the cord to partially enter the grooves and thereby present portions of the body of the cord against which the grooves may exert a substantial pulling force to advance the cord spirally around the capstan.

12. In an apparatus for covering strands, means for applying a textile covering to strands to form a cord, and an axial delivery capstan for withdrawing from the strand-covering means the cord formed thereby, which capstan comprises a cylindrical member having a plurality of longitudinal, rectangular grooves formed therein, each of which grooves is provided with a straight side which is parallel to but displaced from a diameter of the capstan and which forms a tooth for engaging the cord and advancing the cord spirally around the capstan.

13. In an apparatus for covering strands, means for applying a textile covering to strands to form a cord, and an axial delivery capstan for withdrawing from the strand-covering means the cord formed thereby, which capstan comprises a cylindrical member having formed therein a plurality of longitudinal, rectangular grooves having a width substantially equal to the diameter of the cord, each of which grooves has a side which is parallel to but displaced from a diameter of the capstan and which forms a tooth for engaging the cord and advancing the cord spirally around the capstan.

WILLIAM T. BARRANS. 

